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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
31

Desenvolvimento de sistema para seguimento de produto e aquisição de dados do  processo de irradiação em irradiadores de grande porte / Development of system for product tracking and data acquisition of data irradition process in large gamma irradiators

Soares, José Roberto 14 December 2010 (has links)
A esterilização utilizando a radiação ionizante é uma técnica consolidada para o processamento de produtos médicos descartáveis. No Brasil há irradiadores gama em operação com capacidade entre 0.37 PBq (10kCi) a 185 PBq (5 MCi ) utilizando radioisótopos 60Co como fonte de radiação. O trabalho desenvolvido proporciona um controle e registro apurado da aplicação das Boas Práticas de Fabricação (BPF), durante todas as fases de um processo de irradiação, requeridos pelas normas da ANVISA , ISO e recomendações técnicas da AIEA durante o tratamento de alimentos e produtos médicos. Todas as etapas envolvidas no tratamento por irradiação estão mapeados em fluxos de processos (workflow) onde cada agente (participante) tem suas tarefas sistematizadas. A aquisição de dados do processo, o acompanhamento e controle, estão baseados em um conjunto de ferramentas (software livre de licenças) integradas por uma rede de comunicação eficiente, inclusive, utilizando-se recursos da WEB. O desenvolvimento foi realizado para uma unidade com capacidade de processamento a nível industrial , utilizando-se o Irradiador Gama Multipropósito do IPEN/CNEN/USP. O sistema permite a rastreabilidade do processamento, em tempo real, a qualquer participante e também o armazenamento dos registros correspondentes para serem auditados. / The sterilization of medical care products using ionizing radiation is a consolidated technique. In Brazil there are in operation gamma irradiators with capacity between 0.37 PBq (10kCi) 185 PBq (5 MCi) using radioisotopes 60Co as radiation source. The developed work provides an accurate control anda data acquisition for the application of Good Manufacturing Practices during all fases of an irradiadiation process, required by the standards of ANVISA , ISO and IAEA technical recommendations for the treatment of foods and medical products.. All the steps involved in the irradiation treatment are mapped into process flow (workflow) , where each agent (participant) has its systematized tasks. The data acquisition process, monitoring and control, are based on a set of tools (free software licenses) integrated by a network of efficient communication, including the use of Web resources. Using the Gamma Irradiator Multipurpose IPEN/CNEN/USP all the development was performed to be applied in irradiators facilities operating in industrial scale. The system enables a complete traceability of the process, in real time, for any participant and also the storage of the corresponding records to be audited.
32

Desenvolvimento de sistema para seguimento de produto e aquisição de dados do  processo de irradiação em irradiadores de grande porte / Development of system for product tracking and data acquisition of data irradition process in large gamma irradiators

José Roberto Soares 14 December 2010 (has links)
A esterilização utilizando a radiação ionizante é uma técnica consolidada para o processamento de produtos médicos descartáveis. No Brasil há irradiadores gama em operação com capacidade entre 0.37 PBq (10kCi) a 185 PBq (5 MCi ) utilizando radioisótopos 60Co como fonte de radiação. O trabalho desenvolvido proporciona um controle e registro apurado da aplicação das Boas Práticas de Fabricação (BPF), durante todas as fases de um processo de irradiação, requeridos pelas normas da ANVISA , ISO e recomendações técnicas da AIEA durante o tratamento de alimentos e produtos médicos. Todas as etapas envolvidas no tratamento por irradiação estão mapeados em fluxos de processos (workflow) onde cada agente (participante) tem suas tarefas sistematizadas. A aquisição de dados do processo, o acompanhamento e controle, estão baseados em um conjunto de ferramentas (software livre de licenças) integradas por uma rede de comunicação eficiente, inclusive, utilizando-se recursos da WEB. O desenvolvimento foi realizado para uma unidade com capacidade de processamento a nível industrial , utilizando-se o Irradiador Gama Multipropósito do IPEN/CNEN/USP. O sistema permite a rastreabilidade do processamento, em tempo real, a qualquer participante e também o armazenamento dos registros correspondentes para serem auditados. / The sterilization of medical care products using ionizing radiation is a consolidated technique. In Brazil there are in operation gamma irradiators with capacity between 0.37 PBq (10kCi) 185 PBq (5 MCi) using radioisotopes 60Co as radiation source. The developed work provides an accurate control anda data acquisition for the application of Good Manufacturing Practices during all fases of an irradiadiation process, required by the standards of ANVISA , ISO and IAEA technical recommendations for the treatment of foods and medical products.. All the steps involved in the irradiation treatment are mapped into process flow (workflow) , where each agent (participant) has its systematized tasks. The data acquisition process, monitoring and control, are based on a set of tools (free software licenses) integrated by a network of efficient communication, including the use of Web resources. Using the Gamma Irradiator Multipurpose IPEN/CNEN/USP all the development was performed to be applied in irradiators facilities operating in industrial scale. The system enables a complete traceability of the process, in real time, for any participant and also the storage of the corresponding records to be audited.
33

Réalisation d’une plate-forme pour l’optimisation de réseaux de capteurs sans fil appliqués au bâtiment intelligent / Realization of a platform for the optimization of wireless networks sensors applied to the intelligent building

Itoua Engoti, Frank 12 March 2018 (has links)
La thèse porte sur le déploiement d'un réseau de capteurs pour le diagnostic énergétique d'un bâtiment universitaire. Elle s'inscrit dans la thématique Bâtiment intelligent et durable de l'Université de Limoges. Il s'agit au cours de cette thèse, dans un premier temps, d'optimiser l'architecture d'un réseau de capteurs Zigbee ainsi que les méthodes d'interrogation de ces capteurs, pour minimiser la consommation énergétique des nœuds du réseau. On s'appuiera notamment sur des concepts de "compressive sensing" pour augmenter la durée de vie des nœuds autonomes qui pourra être éventuellement renforcée par des organes de récupération d'énergie. / This thesis deals with the roll out of Wireless Sensor Network for the energetic monitoring of an existing building of the University. This work wil be incorporated in the framework of the smart building program of the University of Limoges. The work aims to optimize the architecture of a Zigbee network as well as data collection methods to minimize the energy consumption of the network's nodes. Methods based on the compressive sensing concepts will be investigated to reduce the number of nodes and to extend the lifetime of the nodes. Those methods will eventually be complemented with energy harvesting techniques.
34

Avaliação dos protocolos ZigBee e IEEE 802.11ah através de simulação computacional para aplicação no agronegócio / Evaluation of the ZigBee and IEEE 802.11ah protocols through computer simulation for application in agribusiness

Pablo Luis Fazzanaro 09 June 2016 (has links)
A presença da tecnologia da informação dentro do agronegócio tem avançado e contribuído para a obtenção de melhores resultados para a gestão e, consequentemente, para o proprietário rural. Uma área de pesquisa que tem avançado dentro do setor rural é o monitoramento e a coleta de dados dos animais, em tempo real, possibilitando ao proprietário rural gerenciar seu rebanho, sem a necessidade de se deslocar ao local monitorado ou ao ponto de coleta de dados. A utilização das redes de sensores sem fio para fins de monitoração ainda possui limitações, como por exemplo a limitação do alcance do sinal de transmissão entre os nós sensores. Atualmente as tecnologias de transmissão de dados sem fio em uma rede de sensores alcançam pequenas distâncias, limitando o processo de detecção e coleta dos dados às áreas de pastagem menores. Assim, esta pesquisa teve como objetivo avaliar, através de simulação computacional, dois tipos de protocolos de comunicação sem fio que têm potencial para serem utilizados no monitoramento de sistemas de produção animal em longas distâncias: o protocolo ZigBee e o IEEE 802.1ah. Para a realização das simulações foram utilizados os softwares OMNet++ 4.5 e uma ferramenta de extensão chamada Mixim. Para tanto, foram criados dois cenários (ambientes) para cada protocolo, onde foram definidos: a área de cobertura, em torno de 1.500 metros, topologia da rede sem fio do tipo estática, dois nós para comunicação (um coordenador e um receptor) e as características do cenário. Por meio dos resultados obtidos através de simulação computacional com aplicação das métricas: distância, latência e taxa de perda de pacotes de dados nas simulações, observou-se que o protocolo ZigBee obteve o melhor desempenho em relação à distância de cobertura do sinal e da confiabilidade dos dados transmitidos. / The presence of information technology within the agribusiness has advanced and contributed to better results for the management and, consequently, to the landowner. One area of research that has advanced into the rural sector is the monitoring and collection of animal data in real time, allowing the landowner to manage his herd, without the need to move to the monitored site or the data collection point. However the technology of wireless sensor networks used for this purpose, has limitations and one of them is the signals range factor because, in order to make the data collection is necessary to install sensors and antennas in the pasture to reach the signals. Currently, wireless data transmission technologies in a network of sensors reach short distances, limiting the detection process and data collect to smaller pasture areas. This study aimed to find a long-distance transmission solution to reach areas of larger proportions pastures, and offer the landowner new monitoring resources. The methodology used to find such a solution was through simulations, using two transmission technologies: ZigBee and IEEE 802.11ah. To perform the simulations it was used the OMNet++ software, version 4.5 and an extension tool, called the Mixim. It was created two scenarios (environments) for each protocol, where has been defined: the coverage area of about 1,500 meters, network topology wireless static type, two nodes for communication (a coordinator and a receiver) and the characteristics of the environment. Through the results obtained by computer simulation with application of the metrics: distance, latency and data packets loss rate in the simulations, it was observed that the ZigBee protocol had the best performance in relation to the signal coverage distance and the transmitted data reliability.
35

Safety risks with ZigBee smart devices : Identifying risks and countermeasures in ZigBee devices with an eavesdropping experiment / Säkerhetsrisker med ZigBee smarta enheter

Fältros, Jesper, Alinger, Isak, von Bergen, Axel January 2020 (has links)
With ZigBee being the world’s leading IoT protocol, users are vulnerable to attacks on the wireless communication between ZigBee devices and the information that can be gained from them. For users to protect themselves from potential attacks they need to be aware of what information can be extracted and how it can be countered. Through an eavesdropping experiment, done using three individual sensors from different vendors, various packets with potential for misuse have been identified within the area of building security. With the potential areas of misuse identified, there is also a need for countermeasures against these threats. Countermeasures were identified through a collection of literature that was summarized in order to provide a wide range of alternatives, suitable to different scenarios. The experiment was limited to the functions of the sensors used, as well as traffic using the ZigBee protocol. This study pinpoints a potential for misuse of the ZigBee traffic sent between devices and shows that the ZigBee protocol is fundamentally flawed from a security aspect. Whilst countermeasures exist, they are not applicable to every situation which is why the ZigBee protocol itself needs further development to be considered secure.
36

Integrating Wireless Sensor Technologies into Instrumentation and Telemetry Systems

Araujo, Maria S., Moodie, Myron L., Willden, Greg C., Thibodeaux, Ryan J., Abbott, Ben A. 10 1900 (has links)
ITC/USA 2010 Conference Proceedings / The Forty-Sixth Annual International Telemetering Conference and Technical Exhibition / October 25-28, 2010 / Town and Country Resort & Convention Center, San Diego, California / Recent technological advancements in low-power, low-cost, small-footprint embedded processors, sensors, and radios are resulting in the very rapid growth of wireless sensor network deployments. Wireless sensor networks merge the scalability and distributed nature of networked systems with the size and energy constraints of remote embedded systems. With the ever increasing need to develop less intrusive, more scalable solutions for instrumentation systems, wireless sensor technologies present several benefits. They largely eliminate the need for power and network wiring, thus potentially reducing cost, weight, and deployment time; their modularity provides the flexibility to rapidly change instrumentation configurations and the capability to increase the coverage of an instrumentation system. While the benefits are exciting and varied, as with any emerging technology, many challenges need to be overcome before wireless sensor networks can be effectively and successfully deployed in instrumentation applications, including throughput, latency, power management, electromagnetic interference (EMI), and band utilization considerations. This paper describes some approaches to addressing these challenges and achieving a useful system.
37

Algorithms and Protocols Enhancing Mobility Support for Wireless Sensor Networks Based on Bluetooth and Zigbee

García Castaño, Javier January 2006 (has links)
<p>Mobile communication systems are experiencing a huge growth. While traditional communication paradigms deal with fixed networks, mobility raises a new set of questions, techniques, and solutions. This work focuses on wireless sensor networks (WSNs) where each node is a mobile device. The main objectives of this thesis have been to develop algorithms and protocols enabling WSNs with a special interest in overcoming mobility support limitations of standards such as Bluetooth and Zigbee. The contributions of this work may be divided in four major parts related to mobility support. The first part describes the implementation of local positioning services in Bluetooth since local positioning is not supported in Bluetooth v1.1. The obtained results are used in later implemented handover algorithms in terms of deciding when to perform the handover. Moreover local positioning information may be used in further developed routing protocols. The second part deals with handover as a solution to overcome the getting out of range problem. Algorithms for handover have been implemented enabling mobility in Bluetooth infrastructure networks. The principal achievement in this part is the significant reduction of handover latency since sensor cost and quality of service are directly affected by this parameter. The third part solves the routing problems originated with handovers. The main contribution of this part is the impact of the Bluetooth scatternet formation and routing protocols, for multi-hop data transmissions, in the system quality of service. The final part is a comparison between Bluetooth and Zigbee in terms of mobility support. The main outcome of this comparison resides on the conclusions, which can be used as a technology election guide.</p><p>The main scientific contribution relies on the implementation of a mobile WSN with Bluetooth v1.1 inside the scope of the ”Multi Monitoring Medical Chip (M3C) for Homecare Applications” European Union project (Sixth Framework Program (FP6) Reference: 508291) offering multi-hop routing support and improvements in handover latencies with aid of local positioning services.</p>
38

Performance Study for Co-existing Wi-Fi and ZigBee Systems and Design of Interoperability Techniques

Tang, Yong 21 August 2012 (has links)
Wireless local area networks (WLANs) and wireless sensor networks (WSNs) technologies have been comprehensively developed and deployed during recent years. Since commercial WLAN and WSN products share the same free of license frequency band, the low power, low rate ZigBee based WSNs are vulnerable to the interference from Wi-Fi WLANs. Therefore, it is important to evaluate the performance of ZigBee WSNs that are subjected to interference generated by collocated Wi-Fi WLANs and to design effective counter-measuring techniques should performance improvement is needed. In this research, a versatile testbed for conducting various experiments is established and the ZigBee system’s performance with different clear channel assessment (CCA) modes and energy detection (ED) thresholds are evaluated through extensive experimental measurements in the testbed. It can be concluded from the results that CCA has significant impact on ZigBee’s performance. An existing theoretical analysis approach that is based on the collision time model between ZigBee and Wi-Fi packets is suitably modified to provide analytical evaluation means of the cases we examined. In order to mitigate the interference from the collocated Wi-Fi system, a novel and effective interference-aware adaptive CCA (IAACCA) scheme is proposed and implemented as firmware flashed into Crossbow motes. Experiments confirmed the ability of IAACCA to countermeasure effectively interference generated by Wi-Fi and thus improve the performance of ZigBee WSNs. Finally, a thorough statistical analysis is performed to understand the factors impacting the performance of ZigBee system and is used to further verify our experimental methods.
39

Sistema de extensão de sinais IR usando tecnologia ZigBee

Macedo, Décio da Costa January 2010 (has links)
Tese de mestrado integrado. Engenharia Electrotécnica e de Computadores (Major Telecomunicações). Faculdade de Engenharia. Universidade do Porto. 2010
40

ZigBee for wireless networking

Lönn, Johan, Olsson, Jonas January 2005 (has links)
<p>The past several years have witnessed a rapid development in the wireless network area. So far wireless networking has been focused on high-speed and long range applications. However, there are many wireless monitoring and control applications for industrial and home environments which require longer battery life, lower data rates and less complexity than those from existing standards. What the market need is a globally defined standard that meets the requirement for reliability, security, low power and low cost. For such wireless applications a new standard called ZigBee has been developed by the ZigBee Alliance based upon the IEEE 802.15.4 standard. </p><p>The aim of this diploma work is to design fully functional ZigBee and IEEE 802.15.4 modules, and to evaluate an application in a sensor network. </p><p>This diploma work has resulted in two fully functional ZigBee and IEEE 802.15.4 modules, respectively. It is also shown that ZigBee sensors can be networked wirelessly. Eventually it is the authors hope that the modules will be used within ITN, and also be developed further for new applications.</p>

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